LED downlights with non-circular spots

Abstract

The ubiquitous downlight inhabits our ceilings by the millions. Hot, inefficient, and electrically wasteful, it is next in line for replacement by the latest high-brightness, high-efficacy white LEDs. The conventional downlight configuration of a large incandescent spotlight in a low-cost, ceiling-recessed metal can, represents the culmination of old technology, fated never to improve significantly. Incandescent downlights add greatly both to direct and indirect electrical consumption, with the lamps requiring relatively frequent replacement. The small size of LED emitters means small optical elements can produce much higher-quality beams than incandescent spotlight-lamps can produce. Herein we introduce compact high-luminosity LED downlights with lenses that deliver uniform illumination to delimited targets such as tables. One version utilizes circular lenses and micro-diffuser films to deliver square outputs. The other uses lenses cut to the target shape. In particular, one of these lenses is the first to offer a semicircular spot suitable for gambling tables.

Universidades tecnológicas: o que induziu esse modelo universitário no Brasil

“…Entre estas tecnologias estão o microprocessador inventado em 1971, a primeira calculadora eletrônica portátil a incorporar funções científicas em 1972 (MEHL, 2013), o primeiro computador eletrônico industrial criado em 1969, a fibra ótica e a produção de videocassetes (Sony) desenvolvidos em escala industrial, em meados da década de 1970de (CASTELLS, 1999PARKYN, 2005;SUN, CHENG, 2010). Em 1969, o Departamento de Defesa norte-americano inicia o uso de uma rede eletrônica de comunicação, que mais tarde se tornou a Internet (CASTELLS, 1999;TAIT, 2007).…”

Fabrication of a Beam Shaping Lens for Chip Scale Packaged LEDs

“…Toward this objective, optical engineers used the farfield design approach in which a LED is assumed as a quasi-point light source, and developed various types of secondary optics for which LEDs are designed [5,6,7]. These results, however, still showed relatively large viewing angle for the application of a planar optical system because the miniaturization of their profiles does not lead to a dramatic decrease of the viewing angle nor minimized light loss [6,7,8]. Thus, the design and machining of secondary optics comprise a determinant solution in generating a narrow viewing angle for an ultra-thin optical system.…”

High Illumination Efficiency Linear Light Source Using Light Emitting Diodes

“…Because of advantages of LEDs, considerable effort has been extended on the design of linear illumination sources with LEDs. 3,4) Generally, there are at least two ways to form linear light sources using LEDs: one is a LED array and the other is using one or several LEDs with a light diffusion bar (LDB). Domja ´n et al 5) have reported a linear light source by using a cylindrical parabolic mirror with a focus line coinciding with the internal reflectors of LEDs array as a stripe illuminator for mobile robots.…”